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Is my EGT probe reading correctly?
Author: Matt Liknaitzky Reference Number: AA-00228 Views: 8920 Created: 2012-07-02 18:35 Last Updated: 2015-01-27 18:32 100 Rating/ 1 Voters


If you are unsure whether your EGT Thermocouple probe is reading correctly (MGL Avionics type-K thermocouple), there are a few simple tests you can do:

CANDLE TEST

With the EGT still connected to your instrument, hold the tip of the probe in the hottest part of a paraffin-based household candle. You should get a reading of 930 deg F (500 deg C) on your instrument. If you do, your sender is good!

MILLIVOLT TEST

You can check the sender with a multimeter further as follows, when not connected to your instrument:

First check is with a multimeter set to ohms. You should get very close to zero ohms between the two wires. Next check, set multimeter to millivolt scale. Hold the tip of the EGT probe in the hottest part of a paraffin-based household candle. The flame is about 500 deg C / 930 deg F at the hottest part which should give you a reading of around 20mV.

CHECK POLARITY

Note that the polarity of Type-K Thermocouples is not intuitive, as Red is Negative:

TYPE-K (typical):
YELLOW = POSITIVE
RED = NEGATIVE




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